In late October, just two weeks before the presidential election, the race was in full swing. Elizabeth Edwards, wife of vice presidential candidate Senator John Edwards noticed a large lump in her breast. Eight days later, she returned to her home in North Carolina and saw her doctor.

Katie Couric: "What happened when you went to see your doctor?"

Elizabeth Edwards: "Well, he's a wonderful fellow. And you know he wants to be as optimistic as possible. And he said, you know, he hoped that there was still a possibility that it was something that was benign. But he had made arrangements for me to go get a mammogram and ultrasound, which I did immediately after leaving his office. And the radiologist was not as reassuring. She was pretty clear by looking at her face, what she thought."

Couric: "Really? What did she say? Or was it just her expression?"

Edwards: "She looked at the mammogram. And then she came in… and looked at the ultrasound while I was on the table. And had them also look at my lymph nodes and see if she saw anything there. But you know, she had a pretty grim expression on her face. You know this is serious and we need to do something about this right away."

Couric: "Did your heart sink?"

Edwards: "A little bit. Yeah. Not so much for myself, but you know, I have young children. I have a husband who's is in the middle of all this… of the Presidential election. You know. What exactly is the right course of action here?"

Elizabeth Edwards didn't take long to figure it out. With the presidential race in it's final frantic days, the 55-year-old former attorney soldiered on. She made one campaign appearance after another on behalf of the Democratic ticket. But just hours after Sen. John Kerry and her husband conceded the election, Elizabeth Edwards went to Massachusetts General Hospital where doctors confirmed earlier suspicions. She has breast cancer.

Couric: "What did the doctor tell you initially about your prognosis?"

Edwards: "You know, there are no guarantees on prognosis. I mean, if you don't have metastasis, and we don't know that I don't. But we don't have any indication that I do. Then your prognosis is better. But there are no guarantees with this. Even if you get rid of it, is there some tiny cell someplace that's you know going to grow again."

Couric: "What they call microscopic disease."

Edwards: "Microscopic metastasis. And that happens. You're not going to know it. But you know there are no guarantees in life anyway. And if the one thing that we've learned over the years is that you're going to have to live every day like it's your last day anyway. So you know, this, for me, it's just another reminder of that lesson."

No one has to remind Elizabeth Edwards about the unpredictability and fragility of life. Just eight years ago, her oldest child, her 16-year-old son, was killed in a car accident, devastating the Edwards family.

Couric: "You said something extremely moving I think in People Magazine. You talked about the fact that this has reminded you of the dark period that followed the loss of your son Wade. And you said, ‘To be perfectly frank, there is an odd place after losing a child where you think somehow your life is worth less. This diagnosis is a reminder that this is the life you've got. And you're not getting another one. Whatever has happened, you have to take this life and treasure and protect it. In a sense, having cancer takes you by the shoulders and shakes you.’"

Edwards: "It does It does. I mean, because it's easy to say that I haven't got anything I need to do anymore, anything I want to do at that moment, after you've lost a child. Or anybody who you care a lot about. But this is-- and I have to say, it was part of my prayer every night, every day when I go to the cemetery, you know? ‘Give him back his life and take mine instead.’ And, you know, it's God saying, ‘Not going to do that,’ you know? It's not going to happen. You know, you need to take control of your life and live it to the fullest because this is what you've got. You know, and we--I can't change yesterday. But the truth is, there is another thing that Wade's death has given me in this. And that is this is so far not the worst week of my life, you know? It's given us a real sense of proportion in it. This is something we're given a chance to fight. And we weren't given a chance to fight then. It makes all the difference in the world. And that's why I want the things I can do to make-- that'll make a difference in my future. I don't know whether I have any capacity to do that. But I want to do every single one of them because I didn't get a chance to do any of them for him."

Couric: "What are some of those things?"

Edwards: "Wade died instantaneously or nearly instantaneously. So I couldn't have gotten him the best doctors or, you know, made certain he had whatever attention he needed and been there for him. I have that chance. I have a chance to find the doctors who, you know, who are thinking about this and studying it in the most thoughtful ways so that I can get the very best kind of treatment that's available, which is a great, great opportunity."

Couric: "And coping with Wade's death which is, of course, so unimaginable for every parent. I imagine that it gave you some strength. Or something deep down inside that you had to rely on to get through that awful period that you still have to rely on every day when you think of your son."

Edwards: "Well, you do. I wrote something fairly recently about -- and I think I probably did it back then after Wade died, too. About this sense that you're just sort of falling, you know? And you don't even want to make yourself stop. You're just sort of falling in this world. And it's fine with you if you do because you just can't think -- you just don't have the strength or energy to grab hold of anything along the side of this, you know, of this tunnel that you're falling down endless chasm. And this, you know, this is sort of -- you found a way to do it then. And this is another, you know, now you're falling again. But somehow having been through it once, you realize you just go ahead and grab hold and, you know, do the best that you can."

Edwards: "Well I've now done one. So I have about 14 more weeks of this. Of this process."

Couric: "How are you feeling?"

Edwards: "I'm actually feeling all right. My, you know, medicines were not that hard to take. Good Italian stock. You know, just put anything in me. And so that part's been pretty good. And I'm just looking forward to -- I want to rush through it in a way. But of course I know I can't."

Couric: "When you walked in to get chemo for the first time, were you scared?"

Edwards: "Well? I'll be honest, I wasn't really afraid. I was actually relieved. My feeling was, now I'm doing something about it. You know? As opposed to just being a victim in a sense."

She knows it's going to be a grueling ordeal, so she's taken pains to talk about her diagnosis with her 22-year-old daughter, Cate, and to explain all she can to 6 -year-old Emma Claire and 4 -year-old Jack, the two children she and her husband had after Wade was killed.

Edwards: "We've tried explaining it to them. You know, that Mommy has a bump, and the bump is called cancer. And I'm going to take medicine for the bump, and it's going to make my hair fall out. And I might as well not have said any of the other words. Once I said my hair will fall out, nothing else interested them. And so they're pretty excited about this prospect."

Couric: "Well I understand they laughed uproariously when you told them that your hair would fall out. They thought that was really funny."

Edwards: "They think it's really funny. I don't want to be sort of-- look to them in some way strange if my hair falls out… So I'm going to probably go ahead and shave as it gets close. So that I don't have this sort of dog-with-mange look. Or something."

Couric: "It will be kind of Kojak."

Edwards: "Yeah. Well, maybe."

On more than one occasion during our interview, Elizabeth Edwards managed to find some humor-- even joke about the difficult circumstances now confronting her and her family. Still, inevitably, she is realistic about the future. And for now, it is uncertain.

Couric: "What are you most afraid of?

Edwards: "Well of course I'm most afraid for them. Most afraid that it doesn't turn out as we hope it will. That’s my biggest fear. But there are good things in it too."

For one thing, her decision to go public has given her the opportunity to encourage other women to get yearly mammograms. She hadn't for four years. Now, some women, hearing about her condition, are paying closer attention to their own health.

Edwards: "People are now doing some of the things that I failed to do. They're heeding a lesson of, you know, my negligence about my own health and taking it into their own hands to do something for themselves, which is why I've gotten so many letters from people really supportive. A woman who lives around the corner. Someone else who emailed from the other side of the country saying that they have… with word of my condition, they did their own checks and found that they needed to go to the doctor. And then even found out that they had a diagnosis that was going to need treatment. A woman just started chemotherapy who said, you know, that could have saved her life. Now, you know, did I save her life? I don't know that. But I do know that if I don't speak out, I don't have the chance of having that effect. And the most you could hope for this is that you get the very best out of it that you can get. You know, I can't change the diagnosis. And in truth, only in little ways can I change the ultimate result. But I can change the effect of it. I can change how much it matters to people that they heard about it, that they acted on it. And that's all I'm hoping to do."

Couric: "I know you have said that faith has a lot to do with it too. And you're a person of deep faith."

Edwards: "For John and for me, our faith is real personal. We rely on it, as so many people do. Not just, of course, in times of trouble, but all the times. You know, don't have to turn to God if you look already looking at him, you know? If you're already looking at him for guidance, you don't have to turn to him in times of trouble. But it's always great to know that you've got that. You've got that solace there. That the understanding of what the things that are most important are. And they're not going to change."

Couric: "And Emily Dickinson I know is one of your favorite poets."

Edwards: "Well, when I was a kid, you know? And, of course, back when you're 13 or 14 you memorize all of her poems, especially some of the shorter ones. And so that was her poem about hope is so important because it just-- you have to never, ever stop singing the song, you know? I think that's one of the things I learned through this, through a lot of the process both with Wade and other things, too. That there's not a single reason in the world to give up hope before you have to. Just not a reason in the world. So as long as you can hope, then you need to hold onto it. And I think that's what that was about."

Couric: "Do you remember that Emily Dickinson poem? Can you still recite it?"

Edwards: "Well, parts of it anyway. ’Hope is a thing with feathers that perches on the soul and sings the tune without the words, and never stops at all.’"

Couric: "Tell me about your plans for the future."

Edwards: "Well, I have, you know, told the doctor when we met her, I said, ‘I have 40 years of plans.’ I need 40 years, you know? That's all I'm asking you for is another 40, because I've got so much that I want to do. We'll stay here and get treatment through the end of the school year. At about the end of the school year, we'll sell the house in Washington and move back to North Carolina with-- bought some land in a rural area next to a farm with cows and a creek and a pond. And the kids can grow up in the kind of surroundings that we think are going to be really healthy for them. And continue to get my follow-up treatments down there. And we'll see what life has to offer."

Couric: "And you have a lot to look forward to."

Edwards: "I do. I do. And 40 years to do it."

After Elizabeth Edwards completes four months of chemotherapy, she'll have surgery to remove the tumor, followed by radiation.

Dateline wires the home of a volunteer, Jenny, from top to bottom with hidden cameras. Then she called repairmen to her house for a simple problem we created as a test with Jenny's pool. NBC's Chris Hansen reports.